This description of scientific explanations is from the IQWST curriculum project, which I worked on at the University of Michigan. The IQWST materials support students' learning to construct evidence-based explanations.- fogleman
Why Focus on Scientific Explanations?
Science education reform efforts call for students to develop scientific processes and skills through inquiry. One prominent inquiry practice in both the standards documents and research literature is the construction, evaluation, and communication of scientific explanations. In order to engage in this practice, students must make sense of phenomena they study, and then articulate and defend their understandings to themselves, each other, the teacher, and other audiences.
Constructing and defending scientific explanations should be an important part of science class for three reasons. First, research reveals that practicing scientists construct arguments and explanations that include having to weigh evidence, interpret text, and evaluate claims. This important tool in scientists’ actual practice is a logical component of inquiry learning. Second, research has found that having students engage in argumentation can change their image of science and enhance their understanding of the nature of science. Third, constructing explanations can enhance students’ understanding of science content. In fact, one way to characterize deep understanding of science content is in a student’s ability to explain phenomena. Teachers have an opportunity to assess student understanding by evaluating their explanations.
What is an Evidence-Based Scientific Explanation?
When teaching students to construct explanations, their arguments can be thought of as consisting of three elements:
Claim: a testable statement about what happened
Evidence: data that support the claim
Reasoning: statements that use scientific principles to connect the claim to the evidence
Though evidence-based explanations can be broken down into these three components, the ultimate goal is for students to write such that all three components cohere as a “whole” explanation.
The following sample explanation identifies the three components, and then defines them more thoroughly. This section concludes by highlighting ways in which the units use this framework to foster students construction and defense of scientific explanations.
Scientific Explanation Example
In the 6th grade IQWST Biology unit, students use a computer model of an ecosystem. The system contains foxes, rabbits, grass, and an unknown invasive species. Students examine population fluctuations before and after the invasive species enters the ecosystem in order to determine what the organism eats. Students work in groups to converge on a single answer, and then groups defend their ideas to the whole class. At the conclusion of the lesson, each student writes a comprehensive scientific explanation. Students are then expected to share their explanation with someone at home. The explanation and share-at-home task provide an assessment opportunity for teachers. The following is a sample explanation that a student could write:
(Claim) The invader eats grass. (Evidence) I know this because every time the invader comes in the picture, the grass goes down a lot and the rabbits die out. (Reasoning) This makes sense because of the scientific principle about competition. The invader is competing with the rabbits for grass.
Claim
A claim is a statement of one’s understanding about a phenomenon or about the results of an investigation (experiment). A claim may be made about data that students have been given or that have gathered themselves. If an investigation has independent and dependent variables, then the claim must show the relationship between those variables. In practice, teachers have also found it important to stress that a claim must be a complete sentence that does not begin with “yes” or no,” and that it is typically the first sentence in an explanation. Although it is not necessary that a claim be the first sentence, our experience teaching students to write scientific explanations, consistent with literacy research, has shown that freedom to vary the guidelines is best managed after the guidelines and their purpose have been learned. At first, many students must systematically learn steps that can be revised as they gain control of the process.
The claim is the simplest part of an explanation and often the part students find the easiest to include and identify when they are critiquing others’ explanations. One of the purposes of focusing on evidence-based scientific explanations is to help students include more than a claim (or “simple” answer to a question) in their writing.
Evidence
An explanation must also contain accurate and sufficient evidence in support of the claim. The evidence is what makes the claim believable. Data for explanations can come from investigations students conducts, from observations they makes, from reports of research others have done, or from other sources (e.g. a web-based search). Where possible, explanations incorporate more than one piece of data as evidence. Complex questions may require multiple logical steps to get from the data to the ability to make a claim. In such instances, the explanation must provide evidence for each step.
One goal is to help students understand that data must be marshaled as evidence in support of a particular claim. In complex situations, more than one claim might be made about a single data set. It might also be that more data are available than are necessary to support a particular claim. Students must determine which are the appropriate data to use to support the claim they have made, and what is sufficient data to support that claim. The idea that multiple claims might be made about the same data develops across the curriculum as the inquiry activities become more complex, and students’ options for research questions (and resulting claims and evidence) become increasingly open-ended.
Reasoning
Finally, Ss learn that the accepted scientific understanding or principles that underlie the explanation must be made explicit in a process we have termed reasoning. Reasoning ties in the scientific knowledge or theory that justifies the claim and helps determine the appropriate evidence. The reasoning is important in an argument because it connects to the general knowledge of the scientific community, explaining how particular data support a claim, given what scientists know about the world.
Reasoning is the most difficult aspect of explanation writing for students to understand, and is the most difficult aspect for teachers to teach. Reasoning requires relating general scientific principles—what is already known in science—to the specific question being investigated.
This is an article on assessing scientific explanations in the classroom:
Scientific Explanations Jigsaw Activity - Spring 2011
Teachers can teach students how to write scientific explanations and use these explanations to assess how well their students understand key concepts. In this activity, we'll use a Jigsaw Activity to interpret an article describing how to assess students' explanations as well as how to create a rubric that can be used to assess their explanations for conceptual understanding.
1. Read the text at the top of this page to get a background understanding of what a scientific explanation consists of.
2. In "expert groups," read a small section of the McNeill Krajcik article and create a visual representation of this section on a ~5ft section of whiteboard in the class. Before beginning your whiteboard, you should discuss in your group the main ideas of your passage. This representation should communicate the essential knowledge from your passage. Try to divide up the artistic tasks so that we can finish in a reasonable time.
3. Rearrange into "peer groups" and quickly take turns teaching your portion of the article to your peers.
4. Use the general and specific rubrics to evaluation your scientific explanations.
5. If time permits: Work in affinity groups or individually to sketch out a rubric that you might use for a future scientific explanation assignment. This could be for the informal assessment portion of your assessment project!
Evidence-based Scientific Explanations
This description of scientific explanations is from the IQWST curriculum project, which I worked on at the University of Michigan. The IQWST materials support students' learning to construct evidence-based explanations. -Why Focus on Scientific Explanations?
Science education reform efforts call for students to develop scientific processes and skills through inquiry. One prominent inquiry practice in both the standards documents and research literature is the construction, evaluation, and communication of scientific explanations. In order to engage in this practice, students must make sense of phenomena they study, and then articulate and defend their understandings to themselves, each other, the teacher, and other audiences.Constructing and defending scientific explanations should be an important part of science class for three reasons. First, research reveals that practicing scientists construct arguments and explanations that include having to weigh evidence, interpret text, and evaluate claims. This important tool in scientists’ actual practice is a logical component of inquiry learning. Second, research has found that having students engage in argumentation can change their image of science and enhance their understanding of the nature of science. Third, constructing explanations can enhance students’ understanding of science content. In fact, one way to characterize deep understanding of science content is in a student’s ability to explain phenomena. Teachers have an opportunity to assess student understanding by evaluating their explanations.
What is an Evidence-Based Scientific Explanation?
When teaching students to construct explanations, their arguments can be thought of as consisting of three elements:- Claim: a testable statement about what happened
- Evidence: data that support the claim
- Reasoning: statements that use scientific principles to connect the claim to the evidence
Though evidence-based explanations can be broken down into these three components, the ultimate goal is for students to write such that all three components cohere as a “whole” explanation.The following sample explanation identifies the three components, and then defines them more thoroughly. This section concludes by highlighting ways in which the units use this framework to foster students construction and defense of scientific explanations.
Scientific Explanation Example
In the 6th grade IQWST Biology unit, students use a computer model of an ecosystem. The system contains foxes, rabbits, grass, and an unknown invasive species. Students examine population fluctuations before and after the invasive species enters the ecosystem in order to determine what the organism eats. Students work in groups to converge on a single answer, and then groups defend their ideas to the whole class. At the conclusion of the lesson, each student writes a comprehensive scientific explanation. Students are then expected to share their explanation with someone at home. The explanation and share-at-home task provide an assessment opportunity for teachers. The following is a sample explanation that a student could write:(Claim) The invader eats grass. (Evidence) I know this because every time the invader comes in the picture, the grass goes down a lot and the rabbits die out. (Reasoning) This makes sense because of the scientific principle about competition. The invader is competing with the rabbits for grass.
Claim
A claim is a statement of one’s understanding about a phenomenon or about the results of an investigation (experiment). A claim may be made about data that students have been given or that have gathered themselves. If an investigation has independent and dependent variables, then the claim must show the relationship between those variables. In practice, teachers have also found it important to stress that a claim must be a complete sentence that does not begin with “yes” or no,” and that it is typically the first sentence in an explanation. Although it is not necessary that a claim be the first sentence, our experience teaching students to write scientific explanations, consistent with literacy research, has shown that freedom to vary the guidelines is best managed after the guidelines and their purpose have been learned. At first, many students must systematically learn steps that can be revised as they gain control of the process.The claim is the simplest part of an explanation and often the part students find the easiest to include and identify when they are critiquing others’ explanations. One of the purposes of focusing on evidence-based scientific explanations is to help students include more than a claim (or “simple” answer to a question) in their writing.
Evidence
An explanation must also contain accurate and sufficient evidence in support of the claim. The evidence is what makes the claim believable. Data for explanations can come from investigations students conducts, from observations they makes, from reports of research others have done, or from other sources (e.g. a web-based search). Where possible, explanations incorporate more than one piece of data as evidence. Complex questions may require multiple logical steps to get from the data to the ability to make a claim. In such instances, the explanation must provide evidence for each step.One goal is to help students understand that data must be marshaled as evidence in support of a particular claim. In complex situations, more than one claim might be made about a single data set. It might also be that more data are available than are necessary to support a particular claim. Students must determine which are the appropriate data to use to support the claim they have made, and what is sufficient data to support that claim. The idea that multiple claims might be made about the same data develops across the curriculum as the inquiry activities become more complex, and students’ options for research questions (and resulting claims and evidence) become increasingly open-ended.
Reasoning
Finally, Ss learn that the accepted scientific understanding or principles that underlie the explanation must be made explicit in a process we have termed reasoning. Reasoning ties in the scientific knowledge or theory that justifies the claim and helps determine the appropriate evidence. The reasoning is important in an argument because it connects to the general knowledge of the scientific community, explaining how particular data support a claim, given what scientists know about the world.Reasoning is the most difficult aspect of explanation writing for students to understand, and is the most difficult aspect for teachers to teach. Reasoning requires relating general scientific principles—what is already known in science—to the specific question being investigated.
This is an article on assessing scientific explanations in the classroom:
Scientific Explanations Jigsaw Activity - Spring 2011
Teachers can teach students how to write scientific explanations and use these explanations to assess how well their students understand key concepts. In this activity, we'll use a Jigsaw Activity to interpret an article describing how to assess students' explanations as well as how to create a rubric that can be used to assess their explanations for conceptual understanding.
1. Read the text at the top of this page to get a background understanding of what a scientific explanation consists of.
2. In "expert groups," read a small section of the McNeill Krajcik article and create a visual representation of this section on a ~5ft section of whiteboard in the class. Before beginning your whiteboard, you should discuss in your group the main ideas of your passage. This representation should communicate the essential knowledge from your passage. Try to divide up the artistic tasks so that we can finish in a reasonable time.
3. Rearrange into "peer groups" and quickly take turns teaching your portion of the article to your peers.
4. Use the general and specific rubrics to evaluation your scientific explanations.
5. If time permits: Work in affinity groups or individually to sketch out a rubric that you might use for a future scientific explanation assignment. This could be for the informal assessment portion of your assessment project!